The present disclosure relates to memory devices, and more particularly to data storage devices and methods of operating the same.
Semiconductor memory devices may be typically classified into volatile semiconductor memory devices and nonvolatile semiconductor memory devices. Volatile semiconductor memory devices may perform read and write operations at high speed, while contents stored therein may be lost when the devices are powered-off. Nonvolatile semiconductor memory devices may retain contents stored therein even when powered-off. For this reason, nonvolatile semiconductor memory devices may be used to store contents to be retained regardless of whether the devices are powered on or off.
A flash memory device is one type of nonvolatile memory device. Flash memory devices are widely used as voice and image data storage media in information processing devices, such as solid state drives, computers, handheld telephones, smart phones, digital cameras, camcorders, voice recorders, MP3 players, PDAs, handheld PCs, game consoles, facsimile machines, scanners, and printers. For the past several years, techniques have been developed to provide high-capacity, high-speed input/output and low-power nonvolatile memory devices in solid state drives or mobile devices (e.g., smart phones).
High-capacity and high-speed input/output solutions may be achieved by means of multi-stack chip packages wherein a plurality of nonvolatile memories are connected through the same channel. Reliability of such a data storage system may be reduced due to resistance and parasitic capacitance of unselected nonvolatile memories when performing a read, write or copy-back operation on a selected device. Thus, it is desired to improve the reliability of the data storage system including a plurality of nonvolatile memories connected with each other through the same channel.